In the course of doing research for my micro-essay on the possibilities the Linear Displacement System from I-War has to offer Wing Commander, I found a possibly(?) canon source on the type of in-system drive that is used in the WC-verse. Due to that caveat, I feel no guilt in offering up my system as an alternative, and so what you will see now is a list of the advantages and disadvantages of both systems - specifically those bearing on the setting.

Please peruse at your leisure. I'd like to settle on one of these possibilities next session, though the decision is naturally WingedCat's. I will note that 'implausible' is in neither list of Cons for one reason: neither is particularly plausible. The pseudovelocity drive requires a quantum mechanical event to be stabilized to apply uniformly at the macro-scale, which is extremely improbable. The impulse drive requires ramscoops to be effective to a degree not thought possible, and would not work properly in, say, a solar system - ramscoops work far better in the interstellar medium than in the solar wind itself.



The pseudovelocity drive - which doesn't appear to be a term in common use, even in science fiction - is a drive which applies the effects of velocity that are relative to the engine itself. Examples include the stutterwarp drive in Sword of the Stars and in 2300 AD/Traveller 2300, and the Linear Displacement System from Independence War (which is a little bit better for our purposes because it's not an FTL drive). The simplest and least magical way to do this is a device which generates successive teleportations at high frequency. Since the engine jumps at a frequency, the ship has a speed; since the jumps are all in a direction, that speed has a vector attached, but since the vector relies soley on the direction that the engine is pointed in, there is no inertia associated with the engine and thus it is not true velocity.


  • Allows banking and turning on a dime
  • Has room for CRAZY Oldziey shenanigans
  • Fighter != Planet-killer
  • Allows completely arbitrary interplanetary speeds
  • Extensions of concept encourage carrier strategy
  • No thrust gravity to compensate for - allows for one gravity system on ship


  • No reference in canon
  • Does not affect initial velocity - makes carrier landings problematic (see Catcher Web below)

Nominal Source

Quantum Tunneling is a curious effect of quantum mechanics whereby atomic-scale particles can pass barriers that they should be stuck behind. It is definitely a real phenomenon and has been used in electronics to make things ranging from diodes and transistors to the Scanning Tunneling Microscope. Of particular note is the fact that some particles actually exceed the speed of light when tunneling. Unfortunately for our purposes, this doesn't break relativity because no information can be transmitted this way - they arrive completely random. Also these are zero-spin particles, so not, say…electrons or atoms. Even at lightspeed, quantum tunneling a whole atom (intact!) is borderline impossible. Doing it on a whole ship? From the inside? HA!

Pseudovelocity Drive
Invoke: The Nephilim's drive shudders and it lurches sideways, its velocity pulling it out of the way of Hrrin's cannons.
Compel: The fighter's drive finally fails, pushing it out of the catcher web and into the flight deck. Damage control to your stations!

Impulse Drive


The Impulse Drive as described HERE consists of two parts: a magnetic-containment fusion reactor and an electromagnetic ramscoop. The ramscoop gathers hydrogen fuel, which the fusion reactor heats into plasma and channels into thrust. Because the ramscoop creates drag which increases as velocity does, the impulse drive does have a maximum velocity. 'Afterburners' are actually the reverse - by deliberately weakening the ramscoop, the drag is decreased and therefore the effect of thrust and the top speed are increased. Less efficient ships have a higher top speed but always run at a deficit and require frequent refueling; more efficient ships require fuel for acceleration but when maintaining speed can actually top off their fuel tanks. (Fighters are the former, carriers are the latter.)


  • Listed in the Wing Commander Encyclopedia - though I can't find it anywhere else.
  • Simple afterburners - pinching the ramscoop reduces drag which increases thrust and max velocity…and cuts fuel intake
  • Zero velocity is solar wind - constant between races (if not places)
  • No need to worry about difference between effective velocity and true velocity


  • Drag is forward only - no banking
  • Fusion reactors required - sorry Zinda
  • Rick Robinson's First Law says that a Raptor II fighter at afterburner hitting something will do as much damage as 40 times its weight in nuclear bomb.
  • Stealth - or the lack thereof

Nominal Source

The Bussard ramjet was designed in the 1950s by Robert Bussard, as a way to cut the mass-ratio of interstellar vessels by refueling on the way. While its practicality has been debated and seems especially low now (p-p fusion is hard even at the core of a star, many hydrogen atoms survive billions of years unburned), it did inspire the magsail. As mentioned in my intro, the solar wind isn't as dense as the interstellar medium, and this would probably be less effective. Like…not enough to provide any fuel whatsoever. Also the top speed of a Bussard ramjet is about a thousand times the top speed of a ship in Wing Commander - the ramscoop does create drag, but not THAT much.

Impulse Drive
Invoke: Sitting behind the Stern Lanz, B-4's ramscoop pulls off Zinda's drive plume for a burst of power.
Compel: The unexpected solar flare sends the whole battlefield reeling as their ramscoops balloon like sails before a tempest!

Final note: I threw 'Stealth' as a con in the Impulse Drive category because Every Citizen's Guide states that large ships (which have lower acceleration rates) typically have 1 G of thrust, making them torch-ships, while the main drives in use on a Pseudovelocity drive (and I'm getting sick of typing that word finally) is RCS thrusters. As pointed out in that link, a fusion torch can be seen from light-years away, while RCS thrusters can 'only' be seen from about 3-4 AU. It's harder to see a pseudovelocity drive - especially when you remember that it only needs to thrust to turn - but the engine still draws power and that means a power plant and that means heat. In logs (which to me are more important than canon) we've established that Oldziey ships mostly rely on fission reactors, while Confed ships use more efficient fusion - but both will be extremely hot, need to shed that heat, and therefore be detectable from across the solar system. The only real invisibility in space is insystem FTL, which is the technique that Crest uses to keep its fleet hidden.

As a side note, if you want to talk about the other ways that Wing Commander is 'unrealistic,' pull the pin in the chatroom and seek shelter!

A micro-essay on the possibilities the Linear Displacement System from Independence War has to offer Wing Commander. Just suggestions and hypotheses!
Tweaked 11/26 with some thoughts based on WingedCat's comments about relative velocity…which are even more devastating than I'd realized. Specifically, added the Inertial Compensators and Interplanetary Orbits sections to the Consequences segment.

So, one of the things I've been thinking about lately is fanfiction. I've been reading a fic (Kyon, Big Damn Hero) that's along the 'Rule of Awesome' lines, but it got me thinking about my other preferred line of fanfic, the 'What If' line, and that gave me an urge (mostly passed now) to write a Wing Commander story that was about Wing Commander in a universe where the ships used reaction drives and current extrapolations of weapons technology.

While I was pondering that thought, I started thinking about what a pseudo-velocity drive would do to the setting. Now, a quick google search says that I may be the only person to use the term this way, so I'll define it here:

Pseudovelocity drive: a (superscience!) drive which does not 'accelerate' but simply increases in power, causing motion in the carrying ship which is forward in direction relative to the drive.

(The use of a pseudovelocity drive is the only way a space fighter can swoop, period. It is thus the only way a space fighter can dogfight, though it must be pointed out that none of this line applies to hard-scifi. Except the swooping, that's still technically possible but pointless.) Granted, the LDS in I-War rendered you invulnerable to anything but an LDI (linear displacement interdiction) missile, but we'll ignore that factor by assuming you have to spend more time in real space and the teleportations are small enough that aiming isn't impossible.

The only vaguely (and by vaguely I mean it sounds good but probably isn't possible) plausible pseudovelocity drive I can think of is the successive-self-teleport one, so that's what I'm gonna go with.


Maximum Velocity

The first benefit a modified LDS gives us is maximum velocity. There are three factors involved - the theoretical maximum speed of the drive, the practical maximum speed of the drive, and pseudo-acceleration.

The theoretical maximum speed of a teleport drive is the speed that the ship moves while teleporting. The LDS was a lightspeed jump, so while it was teleporting, the ship was moving at light speed. The Jerome Drive from 2300AD - and the stutterwarp the Liir use in Sword of the Stars - are instantaneous. Each jump, though small, takes no time. But they both have a maximum velocity.

The second number is the practical maximum speed of the drive. This is how often the jump drive can be used. The maximum repeat rate of the LDS was 10%, so it could spend 10% of the time in a light-speed teleport, its rest speed was negligible, so its practical maximum speed was .1 C. The Liir Stutterwarp and the Jerome Drive, OTOH, were both FTL drives - but the Liir drive wasn't particularly faster than the 6ly/turn of the Tarka warp drive, and the Jerome Drive capped at I think about 3ly/day.

I'm not sure if acceleration was particularly meaningful to the Stutterwarp or Jerome drive, but it definitely was to the LDS. For gameplay reasons you couldn't just push a button and be moving at .1 C. Instead you pushed a button and your velocity bar changed from the +1000/-1000 m/s bar to a 0/6.9e8 bar (or something like that). Within a few seconds, velocity was up to 10000m/s and increased at an exponential but easily observable rate. Adjusting the set-speed caused a delayed response as the LDS modified the speed it was providing.

I always thought of it as a spinning drive core making contacts. Obviously sending a gigahertz signal is just a matter of frequency multiplication and switching, but an actual spinning drive core would have real (angular) inertia to fight. For our purposes we can go one better than that - 'obviously' (though this is all completely made-up) a larger ship would require a larger drive core. A larger drive core would have more mass and more angular inertia, and so a carrier or cruiser or freighter would have a lower pseudoacceleration than a frigate than a corvette than a fighter. Granted unless this was ridiculous it wouldn't make much difference in tactical combat but I'll get to that one later.

Too tired/lazy to rewrite that paragraph to fit additional thoughts but replace 'spinning drive core' with 'generator rotor?' Maybe if all output of generator has to be used or problems result? Otherwise there's nothing to stop dropping the voltage through a transistor with a button and killing your speed like a British Harrier pilot during the Falklands War.

John's Law

Important note here. John's Law for science fiction authors states that Any interesting spaceship drive is a weapon of mass destruction. Granted we haven't considered ramming with a pseudovelocity drive, but keep in mind that even if you ramped up the pseudovelocity of a ship to FTL speeds it's actual velocity (and thus its kinetic energy) are still at what they were at rest (orbital velocity). So dangerous, yes - but not to the extent that a fighter drive could irradiate all of Texas.

Fighters and Carriers

There's an interesting point that can be raised about fighters and carriers. In hard science-fiction these generally don't come up because quite frankly the mass ratio is the only thing that matters in your ship until the frame collapses because it can't hold any more weight against the engine. (Note: the Sears Tower is constantly comfortably sustaining 1G.) This is because they use reaction drives, and without friction to cause resistance (hydrodynamics, aerodynamics)… If your ship weighs twice as much, it has twice as much engine, therefore twice as much thrust, and therefor it has the same acceleration.

Nothing I've typed so far goes against that, so I figured I'd throw it out there (it's the thought that hit me that made me put this here on the wiki). The mass-ratio is linear. But what if the energy requirements or mass requirements or whatever of the pseudovelocity drive were some other order, like geometric? Then fighter engines are cheap, cruisers expensive, carriers astronomical. The smaller the fighter, the cheaper the engine, so you'll strip them to the minimum to keep them combat-worthy. That means you need to be able to maintain them, which means fighter carriers, which in Wing Commander consist of everything except the one Corvette design. (By this thought Zinda's ship is easily the most expensive fighter in our group - which makes extra sense when you remember that Oldziey never justified capital ships.) Thought on the Rocketpunk Manifesto tends to stabilize at a few limited designs (the kinetic bus, the laser star, and the kkv drone carrier) with one 'ideal' (and heavily argued-about) size for each design, but a chunk of that is because they're limited by the mass ratio. Even in Diaspora ship size isn't considered an 'interesting' statistic.

Skyscraper Decks

One of the weakest points of deckplans in almost every science fiction thing ever (well, caveat to follow) is the nature of the deckplans. They almost always use airplane/ship layouts which put the engines on the rear end of the ship. This would be true for exactly one type of ship - a spaceplane. (Since it IS an airplane, if you don't want to run your artificial gravity after you've landed, you're better off orienting your artificial gravity to the side.) A larger vessel could, with gravity-assisted reaction drives, land on a planet, so it goes for them, too - so Traveller gets a pass and some parts of Star Trek, too. But with these exceptions aside, every ship which uses reaction drives would be better off aligning its artificial gravity to the engines, since to do otherwise invites confusion between your inertial dampers and your artificial gravity. Assuming you have those. And if you don't you should align your decks to your engines anyway, since to do otherwise gives you artificial gravity into the wall.

Hypothetically, the time between when we start building spaceships and the time when we start building pseudovelocity drives will probably kill airplane deckplans - afterwards we won't do it because we don't think of it. (In general. Plenty of people will do it because they can.) But with a pseudovelocity drive there is no thrust gravity - there's no thrust - and there's no need for inertial dampers - there's no real inertia. (Aside from turning.)

So, yeah, the Roland can have four decks with a long fighter bay on each side, and WingedCat can steal from 99.9999% of the people who sell spaceship deckplans.

Per WingedCat, the fighter deck is the length of the ship to allow for the fighter to get runup for its engines. Deconstruction Rant to follow.

One of the things I read when I was perusing wcnews was a narrative of a Raptor II launching from a carrier (can't remember era or carrier type). The fighter accelerates out the bow of the ship, banks to the right, and slows to a halt to let its wingmates join it. This begs the questions: A) why is it firing a stream of fusion-temp plasma into the middle of a hyper-expensive spaceship? B) why does it accelerate out of the ship….and then STOP? If the launch tube - which doesn't exist, the fighter just runs down the deck and then through the magnetic screen holding the air in - were a magnetic launch system, then using it in the ship would make sense, but it's not. If the ship needed to pick up speed for its ramscoop to engage and its fusion reactor to function, this would make sense, too - but then it stops.

The best fighter launch system in commercial sci-fi is the launch bays on Babylon 5. They're mounted on the outside of the station, with the Starfuries on swivels so that the pilots can walk up to their fighter and step into the cockpit; then the Starfuries swivel down and the launch rack lets go, 'dropping' the fighter into space. There's no need for initial acceleration - if the fighter is moving out of the ship, it's moving out of the ship. There's no need to have the fighter, whatever type of drive it is, move the length of the ship unless you want to use external power to give it a high starting velocity (like the America in Star Carrier - its launch racks put its fighters at relativistic velocity, saving their power for maneuvers and return). There's no indication in WC canon that the launch bay does anything to accelerate the fighters.

As a final note, the America is also a skyscraper design. The fighter hangars are suspended from the mushroom cap of the America, with the launch tubes running 'up' from the hangars. So even if you need that runup, there's no need to orient the ship like a belly-lander. As another side note, Project Rho has an awesome glossary that I'm gonna have B-4 incorporate into her speech.


No real velocity means we're not approaching the speed of light. So relativity doesn't actually come into play at all.


For a while I was wondering what could set Oldzieyan fighters apart from Confederation fighters. Biggest thing - LapisLazuli's idea for Oldziey fighters was about a much greater use of Newtonian physics than Confed doctrine. On the surface, this doesn't work with a pseudovelocity drive, since it throws Newtonian physics on the back burner. But three thoughts here.

One: Oldzieyan fighters use much bigger vectored thrusters, space them further out, and don't worry about the aerodynamic effect because Zinda and Crown Squadron are the only Oldziey fighters to fly through an atmosphere since…ever. (Slight exaggeration.) This means that, following the conventional rules of pseudovelocity drives, Oldzieyan fighters are far more maneuverable than Confed fighters even with the Confed's superior reactor technologies.

Two: the mass ratio doesn't just go away, so the more you can shave off the weight of your fighter the more powerful its engines are. Confed fighters are designed as spaceplanes, with their reactors operational and providing power and heat to their engines in atmospheric flight. This means that their reactors need to be shielded in all directions. Oldziey doesn't have a planet worth living on, so they stick with shadow shielding to cover the pilot.

Three: who said you can't mount the pseudovelocity drive on a gimbal? That's definitely the kind of zany thing that the Oldzieyans would come up with, and it would let an Oldzieyan fighter flip over backwards and shoot the noob Confed pilot on her tail like a Starfury zapping a Raider Delta. Or a British Harrier pilot zapping an Argentinian Mirage. Whatevs.



Wing Commander features afterburners on fighters, and the advantage to those ships with antimatter reactors is that they have unlimited afterburner. (Capships do not have afterburners - their accel is their accel and their max speed is their max speed, period.)

Ironically this is harder with the pseudovelocity drive than a reaction drive, since the space equivalent of an afterburner is throwing oxygen into the hydrogen remass for an extra kick. The best I can think is that part of the normal output of the reactor goes into a capacitor, which can be bled into the pseudovelocity drive for extra output. Really I don't see much difference aside from making the point that Wing Commander has afterburners and Zinda or I should probably use them in maneuvers more often.

Ship Design

There's not much to pull out for capital ships here - just that if the pseudovelocity drive is capable of shrugging off micrometeorites, then you wouldn't need mushroom-cap shields for your ships. Which Wing Commander doesn't have.

It's another matter for fighters. Most space fighters have thrusters on the back, often with intakes on the front. But if the main space drive was pseudovelocity, and if the PVD failed in atmosphere (especially catastrophically, that'd be cool), then since our space fighters are reentry-capable they must be the atmosphere drives (presumably artigrav-assist, since even with a combined cycle engine there's no way a Vampire has the re-mass to hit orbit). This makes sense - regardless of whether it's TBCC or RBCC, our basic fighter design will be somewhat similar to a modern fighter, using the brute force of their advanced technology engines to make up for what they don't have in aerodynamics.

Orbital Traffic Control

A ship that goes from planet to planet, interstellar or not, arrives with the same velocity it had when it started out. So if you're in orbit - which you are - you're moving at orbital velocity the entire trip. (Presumably the drive can compensate by offsetting itself?) Your velocity when you arrive at your destination is exactly the same once you turn your drive off. So it would behoove you to turn your drive off in such a place that your velocity puts you in orbit around your new planet. This means matching the angle and altitude of your insertion to your escape. (Attitude is fine here. Go from an equatorial orbit to polar, no one cares - the issue is the orbital radius and whether you're gonna head straight down or at a perfect tangent.) It implies that everyone in orbit will be moving in the same direction, and presumably at relatively the same speed. Orbital Traffic Control will probably coordinate with your navigation computers to determine what your initial velocity was, as well as how much it changed due to gravity or thrusters during the trip.

Note: this part definitely needs to be thought about or every fighter that flies into the Roland's bay will punch through the hull as soon as it shuts its engine down.

Interplanetary Trips

WingedCat, in #ag_lounge, 11/20:
<@WingedCat> "even if you ramped up the pseudovelocity of a ship to FTL speeds it's actual velocity (and thus its kinetic energy) are still at what they were at rest (orbital velocity"
<@WingedCat> You know that the ship's velocity is relative to the planet it was in orbit of, yes?
<@WingedCat> Something in orbit around Earth, that gets its position translated to Mars, is probably going at high velocity relative to Mars.

I run Diaspora plain, so I'm used to thinking in terms of brachistone trajectories (max thrust, least time), which is why this hit me so bad, first on the (right in the gut!) and then on the (oh my god it's insoluble!) - I usually think of them as straight, but they're actually cycloids, curving to match the velocity of the destination so that the final velocity will fall under escape velocity. Turns out what I should have been thinking about, given low-power rockets and the ability to skip the middle chunk, was instead transfer orbits.

A transfer orbit is a pretty simple thing - they get more complicated depending on the nature of the engine, but they're simplest with a high-impulse motor like a chemical rocket - which is what most of our interstellar probes use (I think). Drawn on a solar map, a transfer orbit is simply an ellipse with two perihelions tangent to the orbit of the source and two aphelions tangent to the orbit of the destination. Ignoring escape velocity for the moment, all you do is start moving at your source planet's velocity. In a circular orbit all points are both the perihelion and the aphelion, so you use your kick motor the first time and BOOM your velocity is halfway between source and destination and you just left one of those perihelions. Six months down the line, as you're approaching the aphelion, so is your destination (which is why transfer orbits have rigid launch windows). Once you hit the aphelion, you use your kick motor the second time and BOOM your velocity matches the destination planet's (hopefully not TOO well or you'll pancake!).

Why is this what I should have been thinking of? Because we do these already, with the chemical rockets on interplanetary probes - and while every gram counts on an interplanetary probe, they also stick with simple, reliable rockets, nothing with the kind of output we can get from a fusion engine. And while they take that aforementioned six months to reach their destination (more or less depending on destination), we can use our * drive to skip that. Kicking at the start to break orbit and set up the rendezvous - kicking at the end to make sure you don't go falling back to where you were and insert into the new orbit - we don't have to worry about those, either. All we need to know is that the reaction engine we need can, in theory, make a burn which adds as much delta-V as they do. And a fusion thruster or even an open-cycle gas-core engine like Zinda's (kidding, treaty or not Kali'd be justified in shooting Zinda in orbit if she tried to deorbit with an engine like that) can make those kinds of delta-V with a ridiculously (awesomely) low mass ratio.

Now, as for the Roland-

Inertial Compensators

—In most sci-fi settings, inertial compensators are the things that keep you from being sliced in half by your seat as your ship accelerates you at 50 Gs. The sole exception I know of is Independence War. In that, inertial compensators are what they call the thrusters as they try to make you feel like you're flying a fat bomber instead of a rocket-propelled brick. Do an end-over turn and the thrusters automatically start firing in such a way that your velocity will - eventually - be retained. Is it perfect? No, because it's trying to be realistic. (Is it succeeding? No, because like WC unhappily reminded me, there's no such thing as a perfect inertial frame of reference and all velocities are relative, which makes I-War's 'natural zero' velocity meaningless.)

This runs into the possibility of bumping Oldziey off their ace-combat throne again (glad I thought of the gimballed PVDs!), because there is one possible situation we need to account for. The Roland takes off from Perry Naval Shipyards, in a circular orbit about 5 AU from Mu Cephei's raging heart. It heads for the jump node and makes a few jumps and winds up in Armstrong. An admiral chooses to move his flag from the Norfolk, which took off from Armstrong orbit earlier (orbital radius, we'll call it 0.9 AU). His shuttle leaves the Norfolk's launch bay with a lateral velocity of about 1 km/s. The Roland's lateral velocity is about 15 km/s. What happens when the shuttle turns off its engine? Cuz whichever frame of reference you choose, it's not gonna be pretty.

The only thing I can think of is unreasonably powerful lateral thrusters and that's kinda….eh.—

Catcher Webs

This serves as the anti-catapult of a carrier, designed to synchronize the velocity of a fighter to the velocity of the carrier as it lands. The catcher web is a complex network of directed gravitational fields surrounding the entrance to the hangar. The fighter lines up with the rear of the carrier, then slowly reduces its pseudovelocity field. The fighter's navigational computer broadcasts its real velocity to the ship, and the ship returns its own real velocity. The fighter's lateral thrusters will begin to bring the two vectors together, but it's not until the ship enters the web that serious changes occur - only Oldziey fighters have the lateral thrust to make a velocity change like that, and Confederation carriers typically have Oldziey fighters shut down their thrusters as they land to avoid the exhaust punching holes in the carrier's engines. Once the fighter is in the web, powerful but localized gravitic fields start pulsing, equalizing the fighter's velocity at the same rate as the fighter's pseudovelocity drops. The end result is somewhat disorienting but otherwise an unnoticeable transition from the fighter's initial velocity to the carrier's final velocity. Once the pseudovelocity drive is shut down, the fighter is at zero relative velocity to the carrier and the carrier web ensures that it falls slowly to the hangar deck, thence to the elevator to return to the flight deck.

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